SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70a6301420bc7f8ca80c066393d834c791feb36999dc2d0e60019ace6e47947c' 
  AND token = 'A6p0riWf8okYvZl42HST15LIX8PBEdwH9jsaBoXRel8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}